Images with loading="lazy" have uncontrollable gray border while loading https://bugs.webkit.org/show_bug.cgi?id=243601

Reviewed by Darin Adler.

Do not paint border while an image is in deferred state.
The test image-loading-lazy-slow.html covers this. However, the current
test runner logic stops page loads before making a pixel snapshot, causing the
image to be painted as a broken image instead of the empty image at the
time of calling takeScreenshot. To fix this, postpone the stopping of page
loads and instead always stop page loads when reseting after the test.

Note that printing tests are not affected since they already made a pixel
snapshot before stopping the page loads.

* LayoutTests/TestExpectations:
* LayoutTests/platform/ios/TestExpectations:
* LayoutTests/platform/mac-wk1/TestExpectations:
* Source/WebCore/rendering/RenderImage.cpp:
(WebCore::RenderImage::paintReplaced):
* Tools/WebKitTestRunner/InjectedBundle/InjectedBundle.cpp:
(WTR::InjectedBundle::didReceiveMessageToPage):
(WTR::InjectedBundle::done):

Canonical link: https://commits.webkit.org/253960@main

Author: rwlbuis

LayoutTests/TestExpectations

@@ -783,7 +783,6 @@ imported/w3c/web-platform-tests/html/rendering/widgets/the-select-element/option
 imported/w3c/web-platform-tests/html/semantics/embedded-content/the-iframe-element/iframe-modify-scrolling-attr-to-yes.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/html/semantics/embedded-content/the-img-element/adopt-from-image-document.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/html/semantics/embedded-content/the-img-element/image-loading-lazy-slow-aspect-ratio.html [ ImageOnlyFailure ]
-imported/w3c/web-platform-tests/html/semantics/embedded-content/the-img-element/image-loading-lazy-slow.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/html/semantics/forms/the-option-element/dynamic-content-change-rendering.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/html/semantics/forms/the-selectmenu-element/selectmenu-option-arbitrary-content-displayed.tentative.html [ ImageOnlyFailure ]
 imported/w3c/web-platform-tests/html/semantics/interactive-elements/the-popup-element/popup-hidden-display.tentative.html [ ImageOnlyFailure ]

Source/WebCore/rendering/RenderImage.cpp

@@ -479,14 +479,17 @@ void RenderImage::paintReplaced(PaintInfo& paintInfo, const LayoutPoint& paintOf
     float deviceScaleFactor = document().deviceScaleFactor();
     LayoutUnit missingImageBorderWidth(1 / deviceScaleFactor);
 
+    if (isDeferredImage(element()))
+        return;
+
     if (context.detectingContentfulPaint()) {
-        if (!context.contenfulPaintDetected() && !isDeferredImage(element()) && cachedImage() && cachedImage()->canRender(this, deviceScaleFactor) && !contentSize.isEmpty())
+        if (!context.contenfulPaintDetected() && cachedImage() && cachedImage()->canRender(this, deviceScaleFactor) && !contentSize.isEmpty())
             context.setContentfulPaintDetected();
 
         return;
     }
 
-    if (!imageResource().cachedImage() || isDeferredImage(element()) || shouldDisplayBrokenImageIcon()) {
+    if (!imageResource().cachedImage() || shouldDisplayBrokenImageIcon()) {
         if (paintInfo.phase == PaintPhase::Selection)
             return;
 

Tools/WebKitTestRunner/InjectedBundle/InjectedBundle.cpp

@@ -222,6 +222,8 @@ void InjectedBundle::didReceiveMessageToPage(WKBundlePageRef page, WKStringRef m
         m_state = Idle;
         m_dumpPixels = false;
         m_pixelResultIsPending = false;
+        // Needed for pixel result pending mode, otherwise a no-op.
+        InjectedBundle::page()->stopLoading();
 
         setlocale(LC_ALL, "");
         TestRunner::removeAllWebNotificationPermissions();
@@ -552,7 +554,10 @@ void InjectedBundle::done()
 
     m_useWorkQueue = false;
 
-    page()->stopLoading();
+    // Postpone page load stop if pixel result is still pending since
+    // cancelled image loads will paint as broken images.
+    if (!m_pixelResultIsPending)
+        page()->stopLoading();
     setTopLoadingFrame(0);
 
 #if ENABLE(ACCESSIBILITY)